With the development of wireless communications technologies, to improve an information transmission rate, a multiple-input multiple-output antenna technology also develops rapidly.
In a transmitter in which multiple transmission channels are arranged, interference often exists among the multiple transmission channels, which affects a transmission effect. To reduce the interference among transmission channels, in the prior art, a space size among transmission channels is increased by means of space shielding; in addition, to meet a requirement of an isolation degree, a physical means such as a screw or a conductive adhesive tape further needs to be arranged between the transmission channels, to implement physical isolation. The increase of the space size and the arrangement of a physical isolation element between the transmission channels increase a transmitter product size.